''Dryopteris aemula'', the hay-scented buckler-fern
or hay-scented fern, is a species of perennial
leptosporangiate fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...
.
Description
''Dryopteris aemula'' grows as a crown of
fronds
A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...
arising from a short ascending rhizome.
The
rachis
In biology, a rachis (from the grc, ῥάχις [], "backbone, spine") is a main axis or "shaft".
In zoology and microbiology
In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this c ...
is dark purple-brown with red-brown lanceolate scales. Leaves are
tri-pinnate, triangular-ovate or triangular-lanceolate, long, often arching, semi-evergreen and pale yellow-green. Scattered small sessile glands grow on the underside or both surfaces of the fronds.
Pinnae
The auricle or auricula is the visible part of the ear that is outside the head. It is also called the pinna (Latin for "wing" or "fin", plural pinnae), a term that is used more in zoology.
Structure
The diagram shows the shape and location of ...
are slightly concave giving the frond a characteristic crisped appearance. The plant is hay-scented.
Sori or spore-producing organs occur in a row down each side of the midrib. The indusium of the sorus is irregularly toothed and edged with sessile glands.
The plant does not reproduce vegetatively and relies upon
spores
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
to generate new individuals.
Taxonomy
Distribution
''Dryopteris aemula'' is confined to the atlantic coastal areas of western Europe and
Macaronesia
Macaronesia (Portuguese: ''Macaronésia,'' Spanish: ''Macaronesia'') is a collection of four volcanic archipelagos in the North Atlantic, off the coasts of Africa and Europe. Each archipelago is made up of a number of List of islands in the At ...
. ''D. aemula'' is highly oceanic in its distribution occurring mostly in the Köppen climate type
Cfb (oceanic climates). Even within Great Britain, it is restricted to western districts and has just a few outlying eastern localities such as
The Weald
The Weald () is an area of South East England between the parallel chalk escarpments of the North and the South Downs. It crosses the counties of Hampshire, Surrey, Sussex and Kent. It has three separate parts: the sandstone "High Weald" in the ...
.
''D. aemula'' reaches the northern limit of its distribution in Britain.
20% of the world population of ''D. aemula'' is in the United Kingdom.
Ecology and conservation
A fern of shady, often rocky, woodlands, usually on acidic soils.
In Britain, it is generally found in
NVC woodland community
W17.
References
External links
National Biodiversity Network's Gateway : grid map for ''Dryopteris aemula'Global Biodiversity Information Facility (GBIF) Data Portal: ''Dryopteris aemula''Ecological Flora of the British Isles : ''Dryopteris aemula''
Further reading
*Clapham A. R., Tutin, T. G., Moore D. M. (1990). Flora of the British Isles. 3rd Ed. Cambridge University Press. Cambridge.
*Page, C.N. (1997). The ferns of Britain and Ireland. 2nd Ed. Cambridge University Press. Cambridge.
*Wardlaw, A.C and Leonard, A (2005) (editors). New Atlas of Ferns & Allied Plants of Britain & Ireland. British Pteridological Society Special Publications no.8.
{{Taxonbar, from=Q1872846
aemula
Flora of Europe